Our urine test strips contain solid phase reagent areas affixed to a plastic stick. They tests provide semi-quantitative determinations of glucose, ketone, pH, blood, nitrite, urobilinogen, bilirubin, protein, specific gravity and leukocytes in human urine.
The test results may provide information regarding the status of carbohydrate metabolism, kidney function, liver function, acid-base balance and urinary track infection.
The test principles are based on various dyes and reagent reactions with components of the urine that lead to colored components, which can be visually detected and/or measured by the instrument.
SUMMARY AND EXPLANATION
The urinalysis test strips are ready to use upon removal from the bottle. The entire reagent strip is disposable. No additional laboratory equipment is necessary for testing. The directions must be followed exactly. Accurate timing is essential to provide optimal results. The strips are packaged in a plastic bottle, containing desiccant. The bottle must be capped tightly to maintain reagent activity.
- Urine test strips.
- Color label chart.
- Instructions for use.
MATERIALS REQUIRED BUT NOT
- Urine collection cup.
- Clock or timer.
- For in Vitro diagnostic use.
- Do not touch test areas of strip.
- After removing a test strip, replace cap on bottle promptly.
- Working area should be free of detergents and other contaminants.
- Store at room temperature, out of direct sun light.
- Do not use after expiration date.
- Do not refrigerate or freeze.
- Store all test strips in the original bottle. Do not remove the desiccant from bottle.
- Close the bottle cap tightly after each use.
- Urine should be collected in a clean container, either plastic or glass. Do not centrifuge.
- If testing cannot be done within an hour after voiding, refrigerate the specimen immediately. Return to room temperature before testing.
- It is especially important to use fresh urine to obtain optimal test results for bilirubin and urobilinogen.
RECOMMENDED HANDLING PROCEDURE
All unused strips must remain in the original bottle, Transfer to any other container may cause reagent strips to deteriorate and become unreactive. Do not remove strip from the bottle until immediately before it is to be used for testing. Replace cap immediately and tightly after removing reagent strip.
GOOD LABORATORY PRACTICE
- Urine collection containers are to be clean with no contamination.
- The urine chemistry analyzer is to be cleaned daily. The instrument is first turned on, an optical calibration and self-test procedure must be performed.
- Each day, the laboratory must run a negative and positive control before each routine test.
- Bring specimens to room temperature before use.
- Remove a test strip from the bottle. Replace cap immediately.
- Inspect the strip. (Discoloration or darkening of reagent test areas may indicate deterioration. Do not use the strip.)
- Immerse test areas of the strip completely in urine and remove immediately to avoid dissolving of reagents.
- To remove excess urine, run the edge of the strip against the rim of the urine container. Hold the strip in a horizontal position to prevent possible mixing of chemicals from adjacent reagent areas. Excess urine may also be removed by gently blotting the lengthwise edge on absorbent paper.
- Compare the test results carefully with the color chart on the bottle label in good light.
- Note: The optimal reading time of each test parameter varies from 30 seconds up to 2 minutes. Changes in color that appear only on the edges of the test areas or after more than 2 minutes are of no clinical significance.
The results are obtained by direct comparison of the test strip with the color blocks printed on the bottle label at the specified times.
Glucose: 10.54% w/w glucose oxidase (aspergillus, 250 IU), 0.2% w/w peroxidase (horseradish, 2,500 IU), 5.0% w/w potassium iodide and 84.3% non-reactive ingredients.
Bilirubin: 1 % w/w 2,4-dichloroaniline diazonium salt and 99 % w/w non-reactive ingredients.
Ketone: 4.5% w/w sodium nitroprusside and 95.5% w/w buffer.
Specific Gravity: 5.0 % w/w bromothymol blue, 58.0% w/w poly (methy vinyl ether), 15.0% w/w sodium hydroxide and 22.0% w/w non-reactive ingredients.
Blood: 6.6% w/w cumen hydroperoxide, 2.0% w/w 3,3',5,5' tetramethylbenzidine, and 91.4% w/w non-reactive ingredients.
pH: 0.1% w/w methyl red, 1.5% w/w bromthymol blue, and 98.4% w/w non-reactive ingredients.
Protein: 1.5% w/w tetrabromphenol blue and 98.5% w/w non-reactive ingredients.
Urobilinogen: 0.6% w/w p-diethylaminobenzaldehyde and 99.4% w/w buffer.
Nitrite: 2.0% w/w p-arsanilic acid, 2.2% w/w a-naphthylamine and 95.8% w/w buffer.
Leukocytes: 0.1% w/w ester, 0.6% w/w diazonium salt, 40% w/w buffer and 59.3% w/w non-reactive ingredients.
Glucose: Large amounts of ketone bodies (50 mg/dl or greater) may decrease color development.
Ketone: Color reactions that could be interpreted as "positive" may be obtained with urine specimens containing medium or large amounts of phenylketones .
pH: Excessive urine on the test strip may wash the acid buffer from the neighboring protein reagent onto the pH area and change the pH reading to an acid pH.
Blood: A false positive can sometimes occur when bacteria are present in the urine. Ascorbic acid or protein may reduce the reactivity of the blood test. Strong oxidizing substances, such as hypochlorite, may produce false positive results.
Nitrite: Any degree of uniform pink color development should be considered positive, however, pink spots or pink edges should not be interpreted as a positive result.
Urobilinogen: Atypical color reactions may be obtained in the presence of high concentrations of
p-aminobenzoic acid. Also false negative results may be obtained if formalin is present.
Bilirubin: Reactions may occur with urine specimens containing large doses of chlorpromazine, which might be mistaken for positive bilirubin.
Protein: False positive results may be obtained with alkaline urine.
Specific gravity: Elevated specific gravity readings may be obtained in the presence of moderate quantities of protein (100 - 700 mg/dl). Specific gravity is increased with glucose in the urine.
Leukocytes: Elevated glucose concentrations or high specific gravity may cause decreased test sensitivity.
Glucose: The kidney normally excretes small amounts of glucose. Concentrations of as little as 0.1g/dl glucose, read either at 10 or 30 seconds, may be significantly abnormal if found consistently. (1)
Ketone: Normally no ketones are present in urine.
Detectable levels of ketone may occur in urine during physiological stress conditions such as fasting, pregnancy, and frequent exercise. (2)
pH: newborn: 5 -7, thereafter: 4.5-8, average: 6. (1)
Blood: Any green spots or green color that appears on the reagent area within 60 seconds indicates blood has been detected and the need for further investigation. (3)
Nitrite: Any degree of pink color after 30 seconds indicates a positive test for nitrite suggesting a clinically significant infection by bacteria. A negative test does not necessarily rule out bacterial infection. (1, 4)
Urobilinogen: In this test the normal range is 0.2 - 1.0 mg/dl. If results exceed the concentration of 2.0 mg/dl, the patient and/or urine specimen should be evaluated further. (5)
Bilirubin: Normally no bilirubin is detectable in urine by even the most sensitive methods. Atypical colors may indicate that bilirubin derived bile pigments are present in the urine sample and are possibly masking the bilirubin reaction. (6)
Protein: Normally urine specimens contain some protein, (0-4 mg/dl) therefore, only persistent levels of urine protein indicate kidney or urinary tract disease. (4)
Specific gravity: In normal adult random urine specific gravity may be from 1.003 to 1.040. Specific gravity will shift according to kidney disfunction. (7)
Leukocytes: Normal urine specimens generally yield negative results; positive results (small or large) are clinically significant. (1,4)
NORMAL VALUE REFERECE
Urobilinogen 0.2 ~ 1 mg/dl
(1 mg/dl =approx. 1 EU)
Studies comparing the our urinalysis test strips and other commercially available strips resulted in greater than 99% agreement with 60 urine samples.
- A. H. Free and H. M. Free " Urinalysis, critical discipline of clinical science" CRC Critical Reviews in Clinical Laboratory Sciences, 481-531, 1972.
- H. Free et. al., "A comparative study of qualitative tests for ketones in urine and serum" Clin. Chem., 4, 323, 1958.
- J. M. Wilson and G. Junger "Principles and practice of
screening for disease" Public Health Papers No. 34, World Health Organization, Geneva, 1968.
- Gershen Tield, L., "Urine and Urinalysis" 3rd ed., W.13, Saunders, Philadelphia, 1948, 17.
- B. Balikov "Urobilinogen in urine and feces" Standard
Methods of Clinical Chemistry, vol. 2, Scligson, D., Ed., Academic Press, New York, 1958, 192.
- J. H. Ivy and J. W. Hurley. Routine urine bilirubin determinations, J.A.M.A., 176, 689, 1961.
- PA.Castaldi et al., "Urinary specific gravity as a measure of renal function" Med. Aust., l, R47, 1960.
If you have any questions about our urinalysis testing intructions or urinalysis results interpretation, please contact us and a customer service representive can help you.